I think I accidently created two accounts and now I cannot change my username:
Oops! There was a problem updating your profile: •This email address is already registered. If it belongs to you, log in above or visit our account recovery page to get access to this account.
I did the recovery process but that did not help! I know that this question was asked multiple times but I cannot find a solution for me. Similar topics for example:
Cannot update my profile - email in use?
Not able to update profile (Email is already registered)
How to merge?